Method for injecting fluids into meat products

ABSTRACT

A plurality of needles is injected into a food product to create a plurality of cavity voids in said product, and a metered quantity of fluid is injected through said needles into said cavity voids while said needles are within said food product, said quantity of fluid being metered to be equal substantially to the volume of said cavity voids.

BACKGROUND OF THE INVENTION

This invention relates to an improved method and means for injectingfluids into meat, fish or poultry products.

The processing of meat products often involves the injection of a brinefluid therein to aid the curing of the meat product.

Prior devices for injecting fluids into meat include a plurality ofneedles mounted upon a vertically reciprocating head. A conveyor movesthe meat below the needles, and stops the movement of the meat. Theneedles then move downwardly to penetrate the meat. While they penetratethe meat they inject fluid into the meat and then are withdrawn. Themeat is then conveyed further and the process is repeated.

Certain problems have occurred in prior art devices. One problempertains to the intermittent movement of the meat. The starting andstopping of the conveyor for moving the meat slows the injection processand further requires additional equipment for sensing the position ofthe meat and for timing the intermittent movement of the conveyorcarrying the meat.

Variations in the uniformity of the distribution of the fluid throughoutthe meat product creates a further problem in existing meat injectionmethods. These variations are created in large measure by the characterof the meat product itself because the fluid easily migrates through thelean meat but not through the fat portions.

Another problem is encountered with prior art devices in properlymetering the amount of liquid or fluid which is injected into the meat.Often the amount of fluid is greater than the amount needed, resultingin spillage and overflow, thereby making it more difficult to maintainsanitary standards. Such excess fluid also detracts from the appearanceof the meat product.

Another problem encountered with the metering of the fluid is thedifficulty in providing the proper amount of fluid when the thickness ofthe meat varies. Thicker portions of meat require a greater amount offluid to be injected, whereas thinner portions of meat require a lesseramount. Similarly, when the needles strike bones or other impenetrableobjects in the meat, they do not penetrate fully, and the presentmetering devices do not satisfactorily accommodate these varying depthsof penetration.

Difficulty is also encountered with present devices in avoiding breakageof the needles when the needles strike bone or other hard matter in themeat. The breakage of needles can shut down the processing operation andthereby be detrimental to the efficiency of the operation.

SUMMARY OF THE INVENTION

The present invention provides an improved method and means forinjecting fluids into the meat, fish or poultry products. The needlehead of the present invention is controlled by cam means for permittingthe head to move in unison with the meat on the conveyor so that theconveyor does not need to start and stop intermittently to receive theneedles.

A plurality of needle heads are provided on the injecting device and areindependently movable with respect to one another so that they maypenetrate to different depths in the meat depending upon variances inthe meat's thickness and in bones found in the meat. Each needle headincludes a metering device for metering the fluid in response to thedepth of needle penetration. The volume of fluid metered correspondsapproximately to the volume of the cavities formed by the needles in themeat.

The device includes means for adjusting the fluid volume depending uponthe depth to which the needles penetrate the meat. If the needles strikea bone and do not penetrate fully, the amount of fluid metered isautomatically adjusted according to the depth of the cavities formed bythe needles. Similarly, the fluid metered is approximately equal to thevolume of the cavities of the needles regardless of how thick the meatis and how deep the needles penetrate the meat.

The fluid is drawn into a metering cylinder during the downward strokeof the needles and is expelled during withdrawal. This permits thedevice to sense the depth to which the needles penetrate the meat and tometer the fluid to correspond to the volume of the needle cavities forthe particular depth to which the meat is penetrated.

Therefore, a primary object of the present invention is the provision ofan improved method and means for injecting fluids into meat products.

The principal object of this invention is to provide a method and meansfor injecting fluid into a meat product or the like which will uniformlydistribute the fluid upon injection in the meat product regardless ofthe lean/fat character of the meat product. A further and related objectof the invention is to control the fluid injection in such a manner thatquantities of fluid are uniformly injected into the fat and leanportions of meat without creating an immediate migration of fluidthrough the lean portions more than through the fat portions at the timeof injection.

A further object of the present invention is the provision of a devicewhich permits the needles to move in unison with the meat being conveyedso as to avoid intermittent starting and stopping of the conveyance ofthe meat.

A further object of the present invention is the provision of a devicewhich meters fluid precisely to the volume of the cavity formed by theneedles in the meat.

A further object of the present invention is the provision of a devicewhich expels fluid only during the withdrawal of the needles from themeat, and which senses the depth to which the meat is penetrated duringthe downward stroke of the needles into the meat.

A further object of the present invention is the provision of a devicewhich adjusts the fluid volume injected into the meat when the needlesstrike bones so that the volume of fluid is equal to the volume of thecavities of the needles when they do not penetrate as deeply as normal.

A further object of the present invention is the provision of a devicewhich adjusts the volume of fluid metered to correspond to the needlevolume even when the depth of the needles varies or when the thicknessof the meat varies.

A further object of the present invention is the provision of a devicehaving adjusting means for providing manual fine adjustment of themetering device.

A further object of the present invention is the provision of a devicewhich includes a plurality of needle heads capable of penetratingindependently of one another to varying depths across the meat width,depending upon meat thickness and the bones in the meat.

A further object of the present invention is the provision of a devicewhich is economical to manufacture, durable in use and efficient inoperation.

BRIEF DESCRIPTION OF FIGURES OF DRAWINGS

FIG. 1 is an elevational view of the device for injecting fluids of thepresent invention.

FIG. 2 is a sectional view taken along line 2--2 of FIG. 1.

FIG. 3 is a sectional view taken along line 3--3 of FIG. 2.

FIG. 3A is a sectional view taken along line 3A--3A of FIG. 3.

FIG. 4 is a sectional view taken along line 4--4 of FIG. 3.

FIG. 5 is a sectional view similar to FIG. 3, but showing the needlesfully penetrated into the meat.

FIG. 6 is an enlarged detailed view of the metering cylinder camadjustment plate.

FIG. 7 is a view similar to FIG. 5, but showing the needles in apartially penetrated position in engagement with a piece of bone in themeat.

FIG. 8 is an enlarged partial sectional view of the metering cylinderand the needles of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, the numeral 10 generally designates theinjection machine of the present invention. Referring to FIG. 1, machine10 includes a table frame 12, comprising a plurality of vertical legs14, a plurality of horizontal bottom members 16, and a plurality of topframe members 18.

Rotatably mounted at opposite ends of table 12 are a pair of conveyorrollers 20, 22 which support a conveyor belt 24. Rollers 20, 22 and belt24 are driven in conventional fashion and therefore the means fordriving these conveyor elements is not shown. Belt 24 supports pieces ofmeat, fish or poultry 26, and moves continuously as opposed to theintermittent starting and stopping action found in prior art injectionmachines.

Mounted to the lower portion of table frame 12 is a motor 28 which bymeans of belts 41, 42 drives pulleys 40, 44. Pulley 44 includes a pivotbearing 46 located radially outwardly from the rotational center thereofso as to provide an eccentric mounting for the lower end of a verticallink 48. The upper end of vertical link 48 is pivotally mounted at 50 toan injector arm 52. One end of injector arm 52 is hinged for pivotalmovement about an axis 54 and the opposite end of arm 52 is pivoted at56 to an injector assembly designated generally by the numeral 58. Ahorizontal link 60 is pivoted at one of its ends to vertical link 48 forpivotal movement about axis 62 and is pivotally mounted at its oppositeend to the lower end of injector assembly 58 for pivotal movement aboutan axis 64.

Rotation of larger pulley 44 causes reciprocating upward and downwardmovement of arm 52 about pivotal axis 54 so that injector assembly 58 isreciprocated upwardly and downwardly as indicated by arrow 66 in FIG. 1.At the same time, link 60 causes the lower end of injector assembly 58to reciprocate in pivotal movement about axis 56 in the directionindicated by arrows 68 in FIG. 1. This reciprocating action caused bylink 60 causes the lower end of injector assembly 58 to movehorizontally in unison with meat 26 as meat 26 is being carried byconveyor belt 24. The timing of movement of arm 52 and link 60 ispre-arranged so that the lower end of injector assembly 58 moves to theleft as viewed in FIG. 1 when arm 52 is in its lowermost position, andthe lower end of injector assembly 58 is moved to the right as viewed inFIG. 1 when arm 52 is in its uppermost position so that needles ofinjector assembly 58 will clear meat 26 when the lower end of injector58 moves to the right. This permits continuous movement of meat 26 ascontrasted with the intermittent starting and stopping of meat 26 as inprevious devices.

Referring to FIGS. 3, 5, 7, and 8, injector assembly 58 includes threesub-assemblies which are referred to for purposes of reference as a ramassembly 70, a needle assembly 72, and a stripper assembly 74. Ramassembly 70 is connected directly to arm 52 for pivotal movement abouthinge axis 56. Ram assembly 70 includes an end plate 76 to which arm 52is pivotally connected. End plate 76 includes a downwardly extendingportion 78 which is pivotally connected at its lower end to link 60 forpivotal connection about axis 64. End plate 76 is welded or otherwisefixed to a pair of horizontal slide bars 80, 82 which extendtransversely across the injector assembly 58 in vertical spaced apartrelation to one another.

Fixed to the upper surface of horizontal slide bar 82 are a plurality ofair spring cylinders 84 in which are mounted air spring pistons 86 andpiston shafts 88. The upper end of cylinder 84 is provided with an airhose connection 90 for charging the upper portion of cylinder 84 with apredetermined amount of air pressure so that piston 86 is yieldably heldagainst upward movement within cylinder 84, and so that piston 86 canovercome the force exerted by the air within the upper end of cylinder84 whenever the upward pressure of piston 86 exceeds a predeterminedforce.

The lower end of piston shaft 88 abuts against the upper surface of aneedle head 92 which is a part of needle assembly 72. Needle head 92includes a cylindrical bore 94 extending horizontally therethrough. Afluid inlet connection 96 provides communication into the interior ofcylinder 94 through a valve opening 98. A check valve 100 (FIG. 8) isbiased outwardly toward valve opening 98 by means of a spring 102. Checkvalve 100 permits fluid to enter cylinder 94 when the pressure withinfluid inlet 96 is greater than that within cylinder 94. However, checkvalve 100 prevents back flow of fluid from cylinder 94 to inlet 96.

A metering piston 104 is mounted within cylindrical bore 94 forreciprocating movement therein, and includes a sealing ring 106 aroundthe outer margins thereof.

Cylindrical bore 94 is also provided with an outlet opening 108 whichprovides communication into a needle manifold 110. A check valve 112 isprovided adjacent opening 108 and is biased toward opening 108 by aspring 114 in such a manner that fluid can flow from cylinder 94 intomanifold 110 when the pressure within cylinder 94 is greater than thepressure within manifold 110, but a back flow of fluid from manifold 110into cylinder 94 is prevented by check valve 112. A plurality of needles115 each have open upper ends in communication with the interior ofmanifold 110 so as to receive fluid therefrom. The lower end of eachneedle 115 is pointed and includes an open end for permitting the fluidto pass from the manifold 110 outwardly through the lower end of needle115.

Extending upwardly from cylinder head 92 is a vertical support member116 which includes a horizontal flange 118 at its upper end. Operativelysecured to flange 118 is a vertical slide bar 120 which has its upperend fixed to flange 118 and its lower end threaded or otherwise fixed tothe upper surface of needle head 92. Ram assembly 70 is adapted forvertical sliding movement on vertical bar 120 by virtue of the slidablemounting of horizontal slide bars 80, 82 over vertical bar 120.

Mounted to the upper surface of horizontal flange 118 is a second airspring cylinder 122.

Stripper assembly 74 includes a piston 124 mounted for sliding movementwithin air spring cylinder 122. A piston rod 126 extends downwardly frompiston 124 and is connected at its lower end to a flange 128 which inturn is fixed to a vertical plate 130. The lower end of vertical plate130 has mounted thereon a stripper plate 132 having holes therein forslidably receiving needles 115.

Mounted to the upper end of vertical plate 130 is a cam plate frame 134having a cam plate 136 pivotally mounted thereon for pivotal movementabout an axis 138. Cam plate 136 includes a cam slot 140 formed therein.

An adjusting pin 142 is threaded to cam plate frame 134 and includes alower end adapted to retentively fit within any of a plurality ofnotches 144 so as to hold cam plate 136 in any of a number of desiredpositions.

Metering piston 104 includes a piston rod 146 which extends outwardlyfrom needle head 92 to a distal end 148. The distal end of rod 146 haspivotally mounted thereto a metering link 150 for pivotal movement aboutan axis 152. Link 150 has an upper end 154 upon which is rotatablymounted a roller bearing 156. Bearing 156 is mounted for rollingmovement within cam slot 140 of cam plate 136.

Link 150 is also pivotally mounted at the approximate longitudinalcenter thereof to an ear flange 158 for pivotal movement about a fulcrumaxis 160. Ear flange 158 is bolted to needle head 92 by a pair of bolts162 which include roller bearings 164 mounted thereon, and which arethreaded into cylinder head 92. Bearings 164 are fitted for slidingmovement within a vertical slot 166 in vertical plate 130 of stripperassembly 74.

The inter-relationship of ram assembly 70, needle assembly 72 andstripper assembly 74 is illustrated in FIGS. 3, 5, 7 and 8. FIG. 3illustrates the relative position of the parts prior to the time thatthe needles commence their downward stroke. FIG. 5 illustrates theassembly in its fully depressed position. Arms 52 cause the movement ofthe device from the position of FIG. 3 to the position of FIG. 5.Downward movement of arms 52 is transferred to ram assembly 70 by virtueof the pivotal connection at hinge axis 56 between arms 52 and endplates 76. In moving from the position of FIG. 3 to FIG. 5, ram assembly70 and needle assembly 72 move in unison with respect to one another.The downward pressure from ram assembly 70 is transferred to needleassembly 72 by virtue of the contact between the lower end of pistonshaft 88 and the upper surface of needle head 92. The air pressurewithin the upper end of cylinder 84 acts as a spring which does notyield in response to normal pressure as the needles are depressed intothe meat. However, FIG. 7 illustrates what happens if the needlesencounter a bone or obstruction 172 in the meat.

When needles 115 engage a bone or obstruction 172, the upward pressurecaused by the resistance of bone 172 is transferred through needle head92 to piston shaft 88 and air spring piston 86. The air pressure in theupper portion of cylinder 84 is chosen so as to yield in response tothis upward pressure caused by obstruction 172, and thus cylinder 86moves upwardly within cylinder 84 against the pressure exerted by theair within the upper end of cylinder 84. Movement between ram assembly70 and needle assembly 72 is permitted by virtue of the slidingengagement of vertical slide bar 120 with respect to horizontal slidebars 80, 82 of ram assembly 70. As illustrated in FIG. 7, needleassembly 72 remains stationary after needles 115 strike obstruction 172,but ram assembly 70 and horizontal slide bars 80, 82 continue downwardlywith the driving force exerted by arms 52.

Stripper assembly 74 moves downwardly with the downward movement of arm52 until stripper plate 132 engages the upper surface of the meat.Stripper plate 132 includes a plurality of openings 168 (FIG. 4) whichsurround needles 115 and permit needles 115 to slide downwardlytherethrough.

When stripper plate 132 engages the upper surface of the meat,resistance caused by the meat to the downward movement of the stripperplate 132 is transferred upwardly through vertical plate 130 to camplate frame 134 and cam plate 136. Piston 124 is driven upwardly withincylinder 122 against the air pressure which is within the upper cylinderof piston 122. The air pressure is chosen in a predetermined manner sothat piston 124 will overcome the pressure in response to stripper plate132 engaging the upper surface of the meat. However, prior to the timestripper plate 132 engages the meat, the air pressure within piston 122forces stripper plate 132 to the position shown in FIG. 3.

The relative movement between stripper assembly 74 and needle assembly72 causes the metering of fluid within cylindrical bore 94 in thefollowing manner. When stripper plate 132 engages the upper portion ofthe meat, the downward movement of stripper plate 132 and cam plate 136ceases, but the downward movement of needles 115 continues. Thisdownward movement of needles 115 and distal end 148 of metering pistonrod 146, causes roller bearing 156 to roll downwardly within cam slot140 from the position shown in FIG. 3 to the position shown in FIG. 5.The downward movement of roller 156 causes metering link 150 to pivotabout fulcrum 160 in a clockwise direction, thereby withdrawing piston104 to the left as needed in FIG. 5. As piston 104 is withdrawn to theleft, it draws fluid inwardly through check valve 100 and fills theportion of cylinder bore 94 to the right of piston 104. The stroke ofpiston 104 is controlled by the depth to which needles 115 protrudewithin the meat. This is true because the stroke of piston 104 iscontrolled by the relative movement between stripper assembly 74 andneedle assembly 72. The greater the relative movement with respect tothese two components, the greater the stroke of piston 104.

The stroke of piston 104 can also be adjusted prior to the operation ofthe machine by virtue of adjusting pin 142 and notches 144. Withdrawalof adjusting pin 142 permits cam plate 136 to be pivoted about axis 138to any of a plurality of desired positions as illustrated in FIG. 6. Thestroke of piston 104 and the pre-set position of cam plate 136 is chosenso as to cause the volume of fluid drawn into cylinder bore 94 to besubstantially equal to the volume of the cavities in meat 26 caused bythe plurality of needles 115.

FIG. 5 illustrates the needles in their lowest position. In FIG. 8, theneedles are shown moving upwardly from their lowermost position, therebyleaving a plurality of cavities 170 in the meat. As needles 115 beginmoving upwardly with the upward stroke of arms 52, cam roller 156 beginsmoving upwardly in slot 140, and the movement of piston 104 is directedto the right so as to begin moving from the position shown in FIG. 5 tothe position shown in FIG. 3. This movement of piston 104 forces thefluid within bore 94 outwardly through outlet opening 108 against checkvalve 112 as viewed in FIG. 8. The fluid moves downwardly throughopening 108 into manifold 110 and thence downwardly and out through thelower ends of needles 115. Because the amount of fluid metered intocylindrical bore 94 is substantially equal to the volume of the cavitiesformed by needles 115, the amount of fluid injected into cavities 170 ismetered exactly so that there is no overflow when the needles are fullywithdrawn from the meat.

If the needles 115 encounter a bone or obstruction 172 as shown in FIG.7, their downward movement is stopped, and therefore the relativemovement between needle assembly 72 and stripper assembly 74 is lessthan the relative movement between these two components illustrated inFIG. 5. Consequently, the movement of piston 104 to the left is lesswhen bone 172 is encountered than would be the case if the needles 115extend downwardly to their full lowermost position. The amount of fluidwithin bore 94 at any given time is always equal to the volume of thecavities of the needles formed in the meat, and therefore exact meteringis provided in the case of encountering a bone, such as shown in FIG. 7.

As illustrated in FIG. 2, a plurality of needle assemblies 72 andstripper assemblies 74 are mounted for independent movement along ramassembly 70, so that should the needles 115 of one needle assemblystrike a bone, and the needles 115 of another needle assembly not strikea bone, the two needle assemblies can move independently of one another.Thus, the depth of the needles will only be short at the point where abone 172 is encountered, and if no bones are present in the remainder ofthe cross section of the meat, the other needle assemblies willpenetrate to the full depth.

While conventional devices cause the lean meat to substantially swell asit is injected with fluid, the present invention substantiallyeliminates such swelling.

From the foregoing, it can be seen that the device accomplishes at leastall of its stated objectives.

I claim:
 1. The method of injecting fluid into a food product selectedfrom meat, fish or poultry, comprising,injecting a plurality of needlesinto said food product to create a plurality of cavity voids in saidproduct defined by the shape of the portion of each needle thatpenetrates said product, and injecting a metered quantity of fluidthrough said needles into said cavity voids while said needles arewithin said food product, said quantity of fluid being metered to beequal substantially to the volume of said cavity voids so as touniformly inject said fluid into the fat and lean portions of said foodproduct without creating an immediate migration of fluid through saidlean portions more than through said fat portions at the time ofinjection.
 2. The method of claim 1 wherein fluid is introduced intosaid cavity voids through said needles as they are being withdrawn fromsaid food product.
 3. A method of injecting fluid into a food productselected from meat, fish or poultry, comprising, injecting a pluralityof needles into said food product to create a plurality of cavity voidsin said product defined by the shape of the portion of each needle thatpenetrates said product, automatically metering a quantity of fluidhaving a volume approximately equal to the volume of said cavity voidsformed by said needles; injecting said metered quantity of fluid throughsaid needles into said cavity voids while said needles are within saidfood product whereby the quantity of fluid injected into said cavityvoids is approximately equal to the volume of said cavity voids formedby said needles so as to uniformly inject said fluid into the fat andlean portions of said food product without creating an immediatemigration of fluid through said lean portions more than through said fatportions at the time of injection.
 4. A method according to claim 3wherein said needles are injected into said food product in a downwardstroke and said needles are withdrawn from said food product in anupward stroke, said metering of fluid being accomplished during saiddownward stroke.
 5. A method according to claim 4 wherein said injectingof fluid through said needles is accomplished only during said upwardstroke.
 6. A method according to claim 4 comprising adjusting thequantity of fluid metered in response to variations in the depth ofpenetration of said needles into said food product.
 7. A methodaccording to claim 6 comprising stopping the downward penetration ofsaid needles before completion of said downward stroke in response tosaid needles striking a hard object within said food product, adjustingthe quantity of fluid metered to be approximately equal to the reducedvolume of said cavity voids which results from said stopping of saiddownward penetration of said needles.
 8. A method according to claim 3comprising sensing the depth to which said needles penetrate said foodproduct, and adjusting the amount of fluid metered according to thedepth of penetration sensed so that said metered fluid will have avolume approximately equal to the volume of said voids regardless of howdeep said needles penetrate said food product.